Ignition apparatus



June 2 P. BROWN IGNI-TIQN AP'PARATU Filed Oct 12,-1925 INVENTOR.

A T'HMNEYS.

- made to do useful Work, the

Patented June 28,1927.

"UNITED flsrATEs P E PS BROWN, or SPRINGFIELD, MASSACHUSETTS.

IGNITION APPARATUS.

- Application filed October 12,1925. Serial No. 62,057.

This invention relates to improvements in ignition apparatus of the so-called reciprocating armature type inwhich ignition currents are intermittently generated. 7

In nnignetos of this type, as heretofore constructed, the ignition spark is produced entirely on one stroke of the reciprocating armature. The other stroke of the armature accomplishes no useful Work. The armature on its idle stroke necessarily pro duces a change of flux in the magnetic circuit but such change has not been utilized. Such change of fiuii' on the idle stroke of the armature sometimes gives rise to a so-called upthrowspark. It always gives rise to a change oi? flux which might be utilized for the production of an electromotive force. The effort, heretofore, has been to stifle the upthrowspark and prevent it from occurring. That is,the upthrow spark has heretofore been considered as a nuisance and effort has been made to keepthe electromotire force induced on theupthrow stroke of the armature at as low, a valueaspossible as by controlling the rate of change of flux and in other ways.

This invention-is concerned withyand has for an'object, the turning of What has heretofore been considered as a nuisance into useiul work ai'id,-inore than that, it is c0ncorned broadly with the utilization, to as full degree as may be possible in each'c'ase, of the hitherto idlestroke of the armature. The necessity for-keeping the electromotive forces generatedv on the upthrow-of the arinatizre at low values no longer exists be cause H cc this GlQCtti'OlHOtlVG force canbe larger it is the better.

The invention is likewise concerned with the adaptation'of ignition apparatusof the reciprocating armature type to high speed, iuulfiicylinder engine work. For such work the apparatus must produce a great many *nxore sparks per minute than has heretofore been iie 1res:.-1ar With one unit, the. time available for a cycle ofarinature operation, including getting the armature on and off its poles anda dwell "ot' the armature oiiits poles is educed toexceedingly sniiill limits. 'ilhc it wouldhave to be worked'cxccedii'igly fast and hard. Accordingly, it an object of the invention to provide an iii-"lure type involving two generating units,

:iion apparatus oi i the reciprocating 'arthat each need notbc worked so hard "and inst; and i to makeach unit during its hitherto idle stroke, help the other unit in a manner broadly analogous to that in which t he weight of the descending car of a funicu-lar railway aids the ascending car.

In carrying out this object the reciprocable armature flux changing means coopcrates with the two magnetic circuits of the two units to increase the reluctance oi each alternately so that when the reluctanceot one is substantially at minimum that of the other is substantially at a maximum. Coupled with this arrangement is acontrol. including normally short. circuited choke wi idin'gs, associated with the magnetic circuits, and means for openingthe circuits of said choke windings, whereby the electro motive forces generated in each unit are caused 'to occur intermittently and SLlbStkli'b tiaily instantaneous. Such control is partic larly characterized by timing the electromotiye force generated in one unit, when its magnetic circuit is substantially open, with that generated, when the other mag netic circuit is substantially closed, and the two units are so connected electrically that the two. electroinotive forces simultaneou induced in each unit during each stroke of.

the reci-p-rocable armature flux changing means are merged, whereby each unit is to ordinated with and contributes to the work oi the other.

()therobjects and advantages will appear in the following description and will be pointed out in the appended claims.

The invention will be disclosed with reference to the one illustrative embodiment ot it shown in the accon'ipanyi'ng drmvings.

in which Fig. 1 is a front elevational view otan ignition apparatusembodying my invention;

tus; and

Fig. 7 is a perspec "ive "View showing parts ofthe ariiiatui'e and its :{lCi'lililtlllg mechanism H in dissociated relation. v

leferring to'these drawings{theigniiion apparatus, disclosed therein, IIIVOlVCS two units which, however, are connected to work in cooperative relation, each assisting and contributing to the work performed by the other. The two units. as shown, are supported from a common frame. driven from a common drive shaft and utilize a common source of magnetic flux. The units, functionally considered, are nevertheless, separate and distinct. These two units being exactly alike, one only will be described in detail and the corresponding parts of the other unit will be designated by the same reference numerals primed.

Each unit has a magnetic circuit including two cores 10, the upper ends of which are connected to a suitable source of magnetic flux, such as the permanent bar magnets 11, and the lower ends of which constitute magnetic poles. Such circuit also includes flux changing means, of the reciprocating type, such as an armature 12, which is mounted for movement toward and preferably into contact with said poles and subsequently away from the sane. As shown, each unit has a separate armature but, while this is desirable and preferred. it is by no means essential in far as the broader aspects of the invention are concerned. The important thing is that the filth: changing means, whether consisting of two armatures or otherwise, is arranged to first increase the reluctance of one magnetic circuit and then the other. The arrangement is such that, when one magnetic circuit is substantially at a maximun'i, the reluctance of the other substantially at a minimum. In the particular embodiment shown. as one armature is just leaving its poles the other armature is just about to contact with its poles. This exact time relation is not essential for all purposes and may be varied within reasonable limits. as desired.

Each unit also includes a generating winding, comprising two coils 13, mounted one on each core 10, and suitably connected to function as one winding. As shown in Fig. 6, these coils are connected in series so that the electromotiye forces generated in each are added, although they may be otherwise connected, if desired. The generating winding of each unit is electrically connected to the generating winding of the other unit so that the electron'iotire forces produced in each are merged in common ignition circuit. As shown in Fig. 6, the winding, including the coils 13, is connected in series by a wire 13': with the winding, including the coils 13, in such a fashion that the electromotive forces, rhich are simultaneously produced in opposite directions in each, are caused to be add.- ed and caused to flow all in the same direction in a common ignition circuit. Such circuit may include a distributor D electrically connected by a wire 15 to one terminal of the connected generating windings, which distributor periodically and successively eonnects the ignition circuit to two spark plugs S. One terminal of these plugs being grounded, the other terminal of the connected generating windings is likewise grounded, as indicated at 16.

The manner in which the generated elec tromotii'e forces are utilized is not important. and that shown is merely illustrative. So also, the manner, in which the two generating windings are connected, is not necessarily essential so far all features of the invention are concerned although it is important and preferred. Any other means for connecting the two generating windings so that the generated electroinotiye forces are i'nerged in a common ignition circuit may be used. if desired, in so far as the broader features of the invention are concerned.

Associated with the magnetic circuit of each unit is a choke winding, herein shown as comprising two coiis 11", mounted one on each core 10 and between the latter and the generating coil 13. These coils may be con nected in any suitable way to function as one choke winding. As shown in F 6, they are connected in electrical series by a wire 18. The purpose of this choke winding, which as usual is normally short circuited, is to restrain substantial flux change in the magnetic circuit until the reciprocating armature flux changing means has reached a predetermined position most favorable for the production of an electromotive force, at which time the choke winding circuitis opened to release the magnetic circuit for a rapid flux change, whereupon an electromotive force is generated in coils 13. The electromotive force generated is therefore intermittent and pra'ctically instantaneous. It occurs at one point only in each stroke of the armature 12. It is therefore essential that the electromotive force induced in one winding be nicely controlled and timed so as to occur simultaneously with the electromotive force induced in the other winding.

its a control, I provide the choke winding described together with interrupter mechanism for opening and closing the circuit thereof. Such means normally causes the choke winding to be in a closed circuit and thus in ilu): cha'i'ige restraining condition. However, when the armature 12 on its down stroke has established an air gap of predetermined degree in one magnetic circuit, the interrupter mechanism opens the choke winding therefor and allows the flux to rapidly die out of such circuit to induce an electromotive force in one generating winding, say for example, that comprising the coils 13. it the same time, the interrupter mechanism opens the circuit of the choke winding sociated with the other magnetic ClICtllL, which has ust been closed by the seating of the armature 12 on its poles. In consequence,

I so

"choke windings.

flux rapidly builds up in this magnetic circuit, resulting in the generation of an electro motive force inthe winding, comprising the COIlS 13.

Thus, two electromotive to ces are sin'iultaneously produced, oneby a. decrease of flux and one byan' increase of flux and these two electromotive forces. are merged in a commonignition circuit so that the one generating unit assiststhe other. As armature 12 nears .its poles, the interrupter mechanisn'i will close the circuits of both Armature 12' will move away from its poles at very nearly the same time that arn'iature 12 engages its poles. lVhen armature 12, inits downward flight, has created a sutiicient air gap in the magnetic circuihotwhich it is a part, the interrupter mechanism wiliaga-in simultaneously open the circuit of both choke windings and two electromotive forces will be simultaneousiy induced in the two generating windings but inopposite directions to those heretofore described.

While any suitable means for effecting the functionsabove attributed to the interrupter mechanism, may be used I prefer for simplicity and convenience to use the two separate int-errupters connected together in eleclikecasing 21 fixed to the frame of the machine. The movable point 20' is carried by a plunger 22, guided in casing Qi'and extendin below the latter and loosely through an opening in a bracket 23, secured to armature At its lower end the plunger 22 carries a head and a spring 25 acts on the latter in normally hold the points 19 and 20 in contact. The head Qd is spacediron'i the "bi-:n-ket 253 and will not be engaged thereby until ari'nature 12 has moved away from its poles a substantial distance and therefore not until an air gap of predetermined degree has been established in the magnetic circuit. It will also be seen that spring 25 will be allowed, on the lll'ltlifTHVOf the armature, to move point 20 into engagement with point 19 before arn'iature 12 is seated on its poles. Tl'ius, these points engage before armature 12 has moved far enough away from its poles toseparate the breaker points 19 and 20. Therefore,the two interrupters operate alternately and. being connected in series in "the choke winding circuits, the separation oieither pair of breaker points will open n'ets 11 the choke winding circuit. The same result could, of course, be obtained by making each armature operate the san'ie interrupter but at di'l'ierent times.

The choke Winding circuits are shown in Fig. ('3. Each movable point 20, being con nected with the metallic frame 01 the 1nachine, is grounded. 'lherei' ore, the two movable points are r zricaliy connected and for convenience such connection has been indicated in Fig. (3 by the dotted line Each of the tired points 19 and 19 are connected by wires 27 with the terminals of the choke winding, comprising the coils l7, and they are also each connected by wires 28 with the terminals of the choke winding, comprising the coils 17. Each choke Winding is therefore short circuited at the proper times by the same means, which comprises the engaged points 19 and 20, the ground connection and the engaged points 19 and 20. The two choke windings are thus arranged in multiple but this arrangement while preferred, is not essential to all features of the invention. The breaker points, according to usual practice, are bridged by a condenser 29 and one condenser, arranged as shown in Fig. 6, will serve for both sets of breaker points. From the foregoing it will be clear that when either set of breaker points open, both choke windings will be opencircuited. Also, it will be clear that these choke winding circuits will be opened twice during each cycle of operation of the armature, once during the down stroke and once shortly after the end or the upstroke while the armature is seated on its poles.

I teferring now to the details of the exemplary apparatus shown in the drawings, the cores 10 are built up from soft iron laminations in the usual way. They are laterally spaced and vertically disposed fiehind the cores 10 in parallel but spaced recesses to receive between them the magnets 11., herein shown as vertical stack of tour. The magnets are ifrictionally held in place in, the recessesby shims 32. The cores 10' are-similarly arranged to receive a second group of magnets 11.. Between the upper extensions of each pair of cores 1() and 10 are placed other sets of laminations which receive between them a third stack oi mag- The laminations 33 are similar to the core laininations except that they lack the depending corev forming parts. All the laminations are clamped together just above coils 13 by boltstla. The cores 10 are tied together abovecoils 13 by a cross bar 35 andfthis bar, together with the correspond- Hit? &

in o; bar U is held in place by the bolts 34.

The cross bars and 30, which are disposed in spaced parallel relation, extend between, and are secured at their ends by screws to a pair upstanding brackets 37, which in turn are mounted on a common bed plate 38. llotatably mounted in brackets and extending therebctween is a drive shaft serving operate both armatures in properly timed relation. Below and parallel with sha t 3%) is a rod l0, mounted at its ends in b 'aclcets 37 and extending therebetween. Shaft 39 and rod l0 are both disposed in the same vertical plane and in a plane which lies between the cores l0 and 10. llod it) serves a common pivotal support for the two armatures 12 and 12. Armature 12 has on its inner face a bracket l1, held thereto by bolts l2, which also serve to hold the desc: ed bracket 23 in place as well as to clamp the laminations of the armature together. The bracket all and the correspondiup bracket ll have hubs which are mounted. to turn on rod so that the armatures l2 and 12' are supported for IlINlGPGHClUDt swingin j movement. These hubs abut at their inner ends. as shown in big". 4;, and at. their outer ends are held speed from the brackets 37 by collars l he armaturcs l2 and 12 may be moved to and from their poles by any suitable mechanism and that shown herein is purely exemplary and forms in itself no partof the present invention. l ly preference and for the particular use above described, I prefer to operate the armature according to the general manner set forth in U. S. Letters Patent I-lo. ljlTQ-lS, g'auted December 1 ltlfll. That is. the armature when the engine is started r when running at low speed may be removed from its poles by an inelastransmi; don from the drive shalt 99 and then driven in its flight away from its poles ii the expansion o'l? previously stressed elas- 1c means it normal ent relv by the inelastic transmission. there met l and when the engine is running speeds the armature may be driven Since iot s oi operating the armature to- 'tl. means for changing from one I tli i tent is unnecessary to describe ii etail herein. wn in the d '31 vines. the a 'inatire hes-e arms are interhtted (Fig. 1) so to to lei lOl 'ulinally on pivot -28. i i ari can er independently and a spring (ne shown) tends to force them apart. The upper zrm all) has a his over- "vin i but capable of being disengaged and ar angular-l spaced 180 (ll ,iees apart. Each consists oi a dwell portion, which is little less than 180 degrees in extent, and similar rise and tall portions, which make up between them the balance oi the periphcry of the cam. The rise and :tall portions are arcs oi circles equal in radius to the radius of the hole in a collar 52, which loosely encon'ipasses the cam and through which the cam acts on the upper arm l6. Cam through lever lb. pushes the armature down away from its poles, at first relatively gradually and then more rapidly. A spring 53 tends to move the armature upwardly, when permittet by :azn 51, and the latter permits the armature to rise at lirstrelatively fast and finally more slowly as the armature nears its poles. The particular armature moveinents described may, obviously, be va ied as desired. This upward movement witl db ninishing' speed as the armature nears its poles is used to secure as quiet a seating ol' the armature on its poles as possible and, taken in conj motion with. the choke winding, which is short circuitcd at the time to diminish the magnetic pull on the armature, acconiplishes its purpose. it reduction oi noise is not desired the speed of the armature on its upthrow stroke may be increaset as de sired.

The operation will largely appear from the foregoing description and need be but summarized here. Each unit of the ignition appa 'atus on the downthrow or its a ma ure produces an electroinotive force in the tormenway and such electroniotive to. i gonen ated every halt revolution of the drive shaft- 39 which for tour cycle, tour 0; linder engine work may be driven at tfllll'llmllllii t speed. The work accomplished by the d owi'i'throw of one arn'iature is, however, aided by the upthrow 0 t the other arina ture. Hence the auab ogy to the funicular railway. The upthrow and the downthrow n'iovements a e coordinated and they cooperate and contribute each to the other. The chainge oi mndition, brought about in the magnetic circuit oi one unit by the upthrow of the armat ire. utilized tov produce an electriunotive torce, which is merged with the elect lUllUiIlVU lorce produced in the other unit in the ordinary way by the downthrow ot the armature. ll ith the aid of the control, such as the choke windings and the interrupter mechanisms, the electroinotive force, generated in one unit by thechange in condition of the magnetic circuit caused by the upthrow of the armature, is caused to. occur simultane ously with the electromotive force generated in the usual way by the downthrow of the armature.

The two units thus divide the work be-. tween, them. each helping the other, during that stroke'of 'the armature which has here tofore been 1dle.

More sparks per minute can be produced without working the generating units as hard or fast as would be necessary if only one unit'wereused. Each armature can dwell on its poles for nearly half a revolution of the drive shaft, whereas if one armature were used and operated twice each revolution by two cams, then onlyone half a revolution would be available for getting the armature on andofi' its p01 and tor getting the dwell of; the armature on its broken and the breaker points open to release the circuit for a flux change, the other mag netic circuit, which is then: closed, shunts the flux-from the first and causes it to die out much more rapidly than it otherwise would. a

In the particular embodiment of the invention illustrated, each armature is moved into contact with its poles while the choke winding of its magnetic circuit is short circuited. This arrangement, while notat all cssentialto the broader-features of the in-. vention, is, as has been above pointed out, desirable when it is desired'to seat the armature as quietly as possibleon its poles. This arrangement is a feature of U. S. Letters Patent No. {488,97 5, granted to me on April 1, 1924. i As brought out in said patent, it is desirable when this arrangem'e'nt'is used, particularly in high speed magnetos, to provide for an extra opening of the breaker points after the armature has been seated on its poles in order to. allow the flux to build up rapidly. This extra opening and closing of the breaker points has been called a flux valve in the trade. It is a feature of this invention that the usual opening and closing so-calledflux valve action that is the open-I ing of the choke winding circuit after the aii'mature has been seated on its poles,-gives rise to the upthrow spark, which as above pointed out, was formerly undesirable. Various methods have, heretofore, been used to kill this spark. This invention incidentally afi'ordsa useful. way of preventing the upthrow spar from doing damage by merging it with the downthrow spark.

ll owcver, with the present arrangement there is no necessity for limiting the socalled upthraw electromotive force, as has heretofore been desirable. Such electromotive force iseXtre-mely useful when, as here, it can be meiged with the downthrow electromotive force and made to do useful work. Accordingly, such upthrow electromotive force can, and desirably is, made as large as possible compatible with the particular conditions of each installation.

The essential feature of this invention con-. sists in securing a cooperative action between two generating units whereby one is made to help the other as above set forth. The de-. tails, therefore, are not important and may be varied in many ways. So also, the par: ticular arrangement and disposition of the parts of the magnetic circuit may be varied as it is only necessary that one part thereof move toward and away from another part in general reciprocating fashion. The term armature as used herein is intended to mean the moving elementof the magnetic circuit and is not used in any limited or strict technicalsense.- The term poles and magnetic poles, as used herein, is intended to mean those parts of themagnetic circuit with which themoving element cooperates and. is not to be construed in a limited or strict technical sense.

The invention has been disclosed herein, in an embodiment at present preferred, for illustrative purposes, but thescope of the invention is defined by the appended claims rather than by the foregoing description.

What I claim is:

1. Ignition apparatus, comprising, two generating units including reciprocable armature flux changing means and means for operating the latter, each unit arranged for the production of an intermittent electromotive force on each stroke of sa d reciproeable means, controlling means arranged to timethe production of the electromotive forces in said units one with the other so that the twointermittent electromotive forces produced in the two units, on each stroke of said reciprocable means occur simultaneously, and connections between said units whereby said electromotive forces are merged.

2. Ignition apparatus, comprising, two magneticcircuits, a common source of flux therefor, a generating winding for each cir-v uit, recjprocable armature, flux changing means forming part of said circuits and op-- crable on each stroke to vary the reluctanceof each circuit, controlling means to time the production of the electromot ive forces in said windings one with the other so that two intermittent lectromotive forces are produced simulti-ineously in the two windings on each stroke of said reciprocable means, and connections between said windings whereby said electron]: tivc forces are n'ierged.

3. ignition apparatus, comprising, two magnetic circuits, a common source of flux therefor, a generating winding for each circuit. reciprocable armature flux changing means forming part of said circuits and operable on each stroke to vary the reluctance of each circuit, and controlling means to time the production of the electromotive forces in said windings one with the other so that two intermittent electromotive forces are pro duced simultaneously in the two windings on each stroke of said reciprocable means.

4. Ignition apparatus, comprising, two magnetic circuits each having a set of poles, a generating winding associated with each circuit, a rcciprocable armature for each circuit to periodically connect and disconnect its set of poles, means for moving first one and then the other of said armatures away from its poles, whereby when the reluctance if one circuit is at a maximum that of the other circuit is at a minimum, controlling means for causing the flux change in each circuit on each stroke of each arn'lature to result in an intermittent electromotive force and for timing the intermittent electron1otive forces so that as one is produced in one vinding during the flight of its armature away from the poles another is simultaneously produced in the other winding while its armature is on the poles, and connections between said windings whereby said simultaneously produced elcctromotive forces are merged.

Ignition apparatus, comprising, two magnetic circuits each having a set of poles, a generating winding for each circuit, a choke winding for each circuit arranged in an electrical circuit which can be opened and closed, reciprocable armature means co- .iperating with said sets of poles to vary the reluctance of said magnetic circuits, means for siumltaneously opening and for subsequently simultaneously closing each choke winding circuit twice during each reciprocation of said armature means and arranged t open said choke winding circuits while the reluctance of the magnetic circuit of one is substantially at a minimum and while the reluctance of the other is substantially at a. maximum, and connections between said generating windings for merging the electromotive forces thus simultaneously produced.

6. Ignition apparatus, comprising, two

magnetic circuits each having a set of poles, a generating winding for each circuit. a choke wim'ling for each circuit arranged in parallel in an electrical circuit which can be opened and closed, rcciprocable armature means cooperating with said sets of poles to vary the reluctance of said magnetic circuits, means for simultaneously opening and for subsequently simultaneously (dosing each choke winding circuit twice during each recipro *ation of said armature means, and connections between said generating windings for merging the electromotive forces thus simultaneously produced.

7. Ignition apparatus, comprising, two magnetic circuit-s each having a set of poles, a generating winding for each circuit, a choke winding for each circuit arranged in parallel in an electrical circuit which can he opened and closed, reciprocable armature means cooperating with said sets of poles to vary the reluctance of said magnetic circuits, means for simultaneously opening and for subsequently simultaneously closing each choke winding circuit twice during each reciprocation of said armature means and arranged to open said choke winding circuits while the reluctance of the magnetic circuit of one is substantially at a minimum and while the reluctance of the other is substan tially at a maximum, and connections be tween said generating windings for merging the electromctive forces thus simultanemisly produced.

8. Ignition apparatus, comprising, two magnetic circuits each having a set of poles, a generating winding for each circuit, a choke winding for each circuit arranged in an electrical circuit which can be opened and closed, reciprccable armature means cooperating with said sets of poles to vary the reluctance of said magnetic circuits, means for simultaneously opening and for subsequently simultaneously closing each choke winding circuit twice during each reciprocation of said armature means, said generating windings being connected in series whereby the electromotive forces simultaneously produced in each are added.

9. Ignition apparatus, comprising, two magnetic circuits each having a set of poles, a generating winding for each circuit. a choke winding for each circuit arranged in an electrical circuit which can be opened and closed. ree procablc armature means cooperating with said sets of poles to vary the reluctance of Faid magnetic circuits, means for simultaneously opening and for subsequently simultaneously closing cach choke winding circuit twice during each reci nocation of said armature means and arranged to open said choke winding circuits while the reluctance of the magnetic circuit of one is substantially at a minimum and while the reluctance of the other is substantially at a lit) till

I t ive forces sinui I a gcncratir maximun'i. said generating windingsbcing connected in series whereby the electromeltaijicously produced in each are added. r

10. Ignition apparatus, comprising, two magnetic circuits each having a set of poles, winding and a choke winding associated with each circuit, a reciprocable armature tor each circuit to periodically connect and (l'sconnect its set of poles, two sets (it cooperating and relatively movable breaker points, connected for operation one to each armature and separable by and during the flight of its armature away from its poles, an electrical circuit which includes said choke windings ands-aid sets of breaker points, the latter connected in series so that the opening of either set will open the circult of said choke windings, means for moving first one and then the other armature away from its poles, and connections between said generating; windings for merging the currents produced therein.

11. Ignition zqiparatus,comprising, two generatii'ig units each adapted intermittently to produce an GlGCtl'Ol'l'lUlllVO itorce, reciprocable armature means tor alteri'iately changing the flux in said units, and tor decreasing thc flux in one while the flux in the other is increased, means controlling the time of production of electromotove force in each unit on each stroke of said reciprocable means, said controlling means arranged to cause the elect-romotive force produced in one unit on a decrease of flux to occur at the same time that an electromotive force is produced in the other unit by an increase in flux, and connections between said units whereby the electron'iotive 't'orces simultaneously produc ,d are merged.

12. In a magneto, having two magnetic ircuits including two sets or? magnetic poles, reciprocable means forming part of said. circuits for connecting first one and then the other of said sets of poles, a normally short circuited choke winding for each magnetic circuit capable of being periodically opened to release its magnetic circuit for a flux cl'i 'zngje, a generating winding for each circuit, means torsinmltan'eously opening both said choke windings whenever either magnetic circuit is broken by said reciprocable means sufficiently to establish an air gap of predetermined degree therein, and connec tions between said generating windings for merging the currents generated by thesi innl ineous flux changes in both magnetic circuits. 7 I

13. In a magi'ieto, having two magnetic circuits lTiCllltlll'tfI two sets of magnetic poles, choke winding and a generating winding associated with eachmagnetic circuit, reciprocable means forming part of said circuits and movable toward and away from each set of poles, said means arranged to in trease the reluctance of one circuit while the re luctance oi the other substantially at a n'iinimum and vice versa, controlling means in circuit with saidchoke windings and. normally maintaining the same short circuited to r train flu-X change in the magnetic circuits, means operable relucta co in each circuit increased to a predetermined degree to operate said controlling means and simultaneously open the choke windi and release both magnetic circuits for a flux change, whereby the tin builds up in one circuit and dies out in the other, and connections between said generating windings to merge the currents thus simultaneously produfid in each. U

In a H15 k, ieto having tw sets of magnetic poles arranged in spaced relation, on armature for each set of poles and movable toward and away from the same, a common member to which both said armatnres are connected for independent pivotal movement, and in -ans "for moving said armatures.

it In a magneto having two sets of mag netic poles arranged in spaced relation, an armature tor eacl of poles and movable toward and away from the same, a common member dispr s d in a plane between said sets of poles to oich both said armatures are c nnected For independent pivotal movement, and means tor moving said armatures.

16. In a magneto, two parallel pairs of: cores, a supporting frame therefor, acommon source of flux connecting the cores of each pair at one end, an armature for ea h pair of cores coo erating with the other ends thereof and movable toward ano away from the same, a common member arranged between the arn'iatures to which each connected for independent swinging movcmen and means for operating; saidarmetures.

17. In a magneto. two parallel pairs of cores. a supportingt'rame therefor, com.- mon source of flux connecting the cores of each pair at one end, an armature for each pair of cores cooperating with theother ends thereof and movable toward and away from the same, a common member arranged between the arinatnres to which each is connected for independent swinging movement and a common drive shaft disposed in a plane between said cores for operating armatures. A

18. In a ma neto lrvino two sets of magnetic poles arranged in spaced relation. an armature for each set of pole, and mounted For movement toward and away from the same. means for supporting: raid ern'iatures for said movement, and a common drive shaft for operating said armatures arranged in a plane between said sets of poles. if

19. In combination, two magneto units, each of the type wherein a reciprocating armature moves into contact with the poles of a, magnetic circuit while the circuit, of the Til c ioke associated with said magnetic circuit closed, means for operating first one and n the other of said arinatures so that one tgneiic circuit is open at a time when the her closed, two interrupters one operted hr each armature and each operable urinethe downthrow of its armature to i a the circuit of the choke winding; assoed ith that magnetic circuit which said armature controls and connections whereby said openingof said choke winding circuit series also to open the circuit of the other choke winding associated with the other magnetic circuitat a time when said circuit is closed.

20. Ignition apparatus, comprising: two magnetic circuits, a generating winding for each circuit, reeiprocahle armature the; changing ineiing forming part of said circuits and operable. on each stroke to *ary the reluctance of each circuit. zind controlling means to time the production oi the clectromotive forces in said windings one with the other so that. two intermittent electroniotive forces are produced siniultaneousl in the two windings on each stroke of said reciprocahle means.

In testimony whereof I have atiixed my signature.

PHELPS BROWN. 

